Single valve vapor push pump

ABSTRACT

Herein disclosed is a pump comprising a chamber including a liquid inlet port. Located within the chamber are: a buoyant valve, responsive to liquid level and vapor pressure within the chamber to open or close said port; a cartridge heater for vaporizing part of the liquid in the chamber; and, a liquid delivery conduit extending from within said chamber to the outside thereof. The heater vaporizes some of the liquid in the chamber and the vapor pressure thereof pushes liquid through the conduit.

United States Patent 1 91 v I 1111 3,819,301

Jaster et a1. '1 June 25, 1974 1 SINGLE VALVE VAPOR PUSH PUMP I I Primary ExaminerWil1iam L. Freeh Us] Mentors gfi gl gi g ififi g fikF G Assistant ExaminerRichard E. Gluck Attorney, Agent, or FirmPatrick D. Ward; Joseph J.

[73] Assignee: General Electric Company, Cohen; Jerome C. Squillaro Schenectady, NY.

[22] Filed: Nov. 29, 1972 [21] Appl. No.: 310,662 57] ABSTRACT [52] U 8 CI 417/209 l lerein disclosed is a pump comprising a chamber in- 51 [lit (11.2.? f minis/ iaison 1/18 cluding a quid inlet Located within the Chan" [58] Field of Search 417/2O7 208 209 126 her are: a buoyant valve, responsive to liquid level and vapor pressure within the chamber to open or close said port; a cartridge heater for vaporizing part of the liquid in the chamber; and, a liquid delivery conduit [56] References Cited extending from wlthm said chamber to the outside UNITED STATES PATENTS thereof. The heater vaporizes some of the liquid in the 2,909,186 10/1959 Larson 137/202 chamber and the vapor pressure thereof pushes liquid 3,065,712 11/1962 Buchanan et a1. 417/209 h h the d i 3,200,763 8/1965 Lippincott 417/209 FOREIGN PATENTS OR APPLICATIONS Y 6 Chin's, 1 Drawing Figure 673.740 10/1929 France ..417/134 1 SINGLE VALVE VAPOR PUSH PUMP CROSS-REFERENCES TO RELATED PATENT v APPLICATIONS LIQUID FILM EVAPORATION FROM 'GROOVED EVAPORATOR SURFACE AND VAPOR PUSH PUMP FOR CIRCULATING CONDENSATE.

The entire right, title and interest in and to-the inventions described in the aforesaid patent applications, as well as in and to the aforesaid-applications, and the entire right, title and interest in and to the invention herein described, as well as in and to the patent application of which this specification is a part, are assignedv to the same assignee.

BACKGROUND OF THE INVENTION The invention, hereinafter illustrativelydisclosed in connection with an accompanying drawing pertains to a novel pump for pumping liquids; and,more' particularly, to a pump wherein part of the liquid delivered therein; a conduit having inlet and outlet openings at opposite ends thereof, said inlet opening being normally submerged in the liquid in the chamber and said outlet opening being above the liquid level of said body of liquid, said conduit passing through said housing and being in sealed relationship therewith; means operable for vaporizing at least part of the liquid within the chamber to enable the vapor pressure of the vapor so produced to push the remaining liquid in said chamber into said inlet opening of said conduit and through said conduit; and, a buoyant valve body located within said EVAPORATIVE COOLING SYSTEM EMPLOYING thereto for pumping is vaporized and the vapor pressure so developed is employed for forcing, or pushing, the remaining liquid through a suitable liquid delivery conduit.

Because it is appropriately descriptive, the subject pump is often referred to hereinafter, in the specification and claims as a vapor push'pump.

Conventional mechanical pump units have, among others, the following limitations respecting their performance: (1) limited reliability due to the inclusion of many moving parts; and (2) the inability of many, but.

not all, such conventional units to effectively pump saturated liquids becauseof cavitation problems. Since reliability in mechanical pump units is generally associated with the number of moving parts efforts have been made to reduce such moving parts to a minimum. For example, in a conventional pump unit such moving parts include the prime mover. (e.g., electric motor),

mechanical coupling, impeller or diaphragm, bearings and etc.

SUMMARY OF THE INVENTION One objectof the invention is to provide anovel pump employing as few moving parts as possible to enhance its reliabilityan'd also to enable less expensive construction and maintenance.

Another object of the invention is'toprovide a novel pump which is capable of pumping saturated liquid.

Briefly, in accordance with an illustrative embodiment of the invention, there is provided a vapor push pump comprising: a housing adapted to be submerged below the liquid level of a body of liquid to bepumped, said housing including a chamber therein, a port through which liquid from said body of liquid may enter the housing and at least partly fill said chamber chamber, operable as a function of said liquid level, its own'weight, the level of liquid in said chamber and the vapor pressure in said chamber for closing or opening said port.

Other objects, the various features and advantages of the invention, as well as a fuller understanding thereof will appear by referring to the following detailed description, claims and drawing.

THE DRAWING In the drawing there is schematically shown a vertical cross section of a vapor push pump in accordance with the invention.

DESCRIPTION OF A PREFERRED EMBODIMENT In the schematic cross section drawing a vapor push pump is designated, generally, by the reference number 10. The pump 10 includes a housing 12 within which there is defined a chamber 14. The housing 12 is provided with a port 16, or opening, at the top thereof so that liquid from an external body 18 of liquid may enter the port 16 andat least partly fill the chamber 14. The housing 12 is submerged in the external body 18 of liquid whose head Hx, or liquid level, is indicated in the drawing with reference to the shown datum line, the top of housing 12. Also, at the top of the housing 12 two additional openings 20 and 22 are provided. The opening 20 has one end of a conduit 24 coupled thereto. The conduit 24, as shown, has another opening 21 at the opposite end which is above the level of the body 18 of liquid. The opening 20 with conduit 24 serve as a vapor vent, the action of which is described in detail hereinafter. Another conduit 26 which, as shown, is relatively long passes through the opening 22 in the housing 12. The conduit 26 is sealed to the housing 12 where it passes through the opening 22. As shown, the elongated conduit 26 has an inlet opening 28 at the lower end thereof and an outlet opening 30 at the opposite or upper end thereof. As will be appreciated from the discussion hereinafter appearing the conduit 26 acts as a liquid delivery tube, or riser, in that liquid within the housing 12, in chamber 14, is pushed through the inlet opening 28 and flows upwardly in conduit 26 where it is ultimately discharged at the outlet opening 30 thereof. As indicated in the drawing, the outletopening 30 of conduit 26 extends beyond the extemal body 18 of liquid, above its level or head Hit. The inlet opening 28 of'conduit 26 is normally submerged in liquid in chamber 14 within housing 12.

heater 36 is located. A pair of electrical leads 38 having an end thereof electrically connected with the heater 36 extends in sealed relationship through the housing 12 to the outside thereof, as shown. As shown, the upper portion of the bore 34 communicates with a wider diameter cylindrical space 40 which is closed at its upper end by a seal 60, or cover. The body 32 also includes a cylindrical well 42 within which the inlet opening 28 of conduit 26 is positioned. Between an outside wall surface of the body 32 and the inside wall surface of housing 12 there is provided the space 44, as shown in the drawing. The body 32 also includes another bore 46 which communicates the aforesaid space 44 with the other bore 34, within which heater 36 resides.

Mounted by suitable means (not shown) at the upper portion of the cylindrical space-40 is a bent vapor outlet tube 48, an inlet end of which is within the cylindrical space 40 and the outlet end of which extends above the uppermost part of the sealing cover 60. The vapor inlet opening and the vapor outlet opening of the vapor outlet tube 48 are designated by the reference numbers 50 and 52, respectively. I

Mounted within the chamber 14 is a valve body 54 which is shown schematically in the drawing. The valve body 54 is buoyant and may float upwardly or downwardly depending on the liquid level in chamber 14; the upward and downward movement of the valve body 54 being suggested by the arrows in the drawing. The valve body 54 includes a number of openings 58 therein for the passage of vapor. Suitable stop members (not shown) limit the downward as well as lateral movement of valve body 54. Suffice it to say that: in its uppermost position the valve body 54 seals and closes ofl' the port and opening 16 and 20. The valve body 54 includes a flexible diaphragm 56 (e.g., a thin silicone rubber sheet) at the top thereof, as indicated, which facilitiates closure of the port 16 and the opening 20 inasmuch as portions of the diaphragm 56 flex and enter a short distance into port 16 and opening 20 thereby closing these apertures.

As will be more fully appreciated from the discussion hereinafter set forth the body 32 is fashioned from a material having a relatively low thermal conductivity and low thermal diffusitivity in order to provide good thermal insulation for the system. Heat generated by the heater 36 is, thus, efficiently used to raise the temperature of the liquid surrounding the heater and is not wastefully employed in heating the body 32, housing 12, the other components of the vapor push pump or the body of liquid 61 within the chamber 14.

OPERATION The valve body 54 due to its own weight is situated more or less in the position shown in the drawing (and retained by stop members) such that the port 16 and the opening are open. As a result, liquid from the body 18 of liquid enters the port 16 due to the pressure head Hx of the body 18 of liquid. The liquid thus admitted through the port 16 begins to fill the chamber 14 of housing 12. When the liquid level within chamber 14 reaches the valve body 54 the buoyancy of the valve body 54 causes valve body 54 to float upwardly in the liquid thereby closing the port 16 as well as the opening 20. Some of the liquid within the chamber14 enters the space 44 and, thereafter, enters the bore 46 from whence it passes to the other bore 34 where it surrounds the heater 36. The heater 36 adds heat to the surrounding liquid thereby converting some of the liquid into a vapor which rises into the space 40. Vapor from the space 40 enters the inlet opening 50 of the tube 48 and passes upwardly therethrough to the outlet opening 52. From the outlet opening 52 vapor from the tube 48 exits through the openings 58 provided in the valve body 54. Vapor exiting from the openings 58 enters the main chamber 14 where it accumulates and exerts pressure on the liquid below. The vapor contained in the upper portion of chamber 14 also acts on the underside of the diaphragm 56 to help maintain the diaphragm 56 in a position closing the port 16 and the opening 20. In addition, the vapor contained in the upper portion of the chamber 14 exerts pressure on the liquid in the lower portion of chamber 14 thereby pushing or forcing said liquid into the riser conduit 26 through the inlet opening 28 thereof. The liquid entering the inlet opening 28 passes upwardly through conduit 26 and is discharged at the outlet opening 30 thereof. When the liquid level within the chamber 14 has fallen to a level a little below the lower periphery, or rim of the conduit 26 within the well 42, conduit 26 drains free of liquid and the vapor within the chamber 14 and within the conduit 26 is, in effect, vented through the conduit 26 and discharged at outlet opening 30. Accordingly, the vapor pressure within the chamber 14 i'srelieved and the valve body 54 falls due to its own weight, thus opening the port 16 and the opening 20.

A feature of the invention relates to the relationship of the well 42 to that portion of the conduit 26 which includes the inlet opening 28. More particularly, the diameter of the well 42 is relatively small in order to accelerate vapor venting through conduit 26. In this connection, it is important to free the inlet opening 28 of conduit 26 from liquid at the end of the aforesaid cycle. In order to do this enough mass must leave the pump through the conduit 26 so that the liquid level in chamber 14 is considerably lower than the opening 28 of conduit 26. Since only vapor at this portion of the cycle leaves the pump 10 through the conduit 26 a volume of liquid proportional to the surface area of the liquid in well 42 must be vaporized. Hence, a relatively small diameter of well 42 is necessary so that a relatively small volume of liquid need be vaporized in order to achieve the venting through conduit 26 in a relatively short period of time. If the diameter of the well 42 were relatively large a longer time period would be required to vent the vapor. When the liquid level in the well 42 sinks to the level of the inlet opening 28 of conduit 26 liquid surface tension between the liquid and the conduit 26 does not permit an immediate and abrupt venting of vapor through conduit 26. Instead, the liquid level has to sink to a somewhat lower level while a film of liquid still attaches to the outside surface of conduit 26. When the liquid level in well 42 descends even further the liquid film will partially break permitting a small amount of vapor to vent in the form of bubbles through conduit 26. Small instabilities on the surface of the liquid in well 42 will alternately restore and break the liquid film attached by surface tension to the outside of conduit 26. A phenomenon called chugging flow occurs wherein vapor bubbles drive slugs of liquid upwardly through conduit 26. These slugs at some point in their travel break down and become a liquid film again and form a countercurrent liq- I the diaphragm 56 sealing the port 16 and opening 20 closed. Thus, by means of the aforesaid relatively narrow diameter (as indicated in the drawing of v the well 42 the aforementioned instabilities occasioned by chugging flow are reduced to an acceptably short time period because the mass of liquid to be vaporized is reduced proportionately to the lesser area.

Another feature of the invention is the inclusion of a vapor venting conduit 24. If such a venting conduit 24' were not provided then when the float valve body 54 moved downwardly opening the inlet port 16 vapor within the chamber 14 would have no other course but to escape through the port 16 while liquid from the body 18 tries to enter the chamber 14 through the same port 16. Thus, the incorporation of a vapor venting circuit 24 with its opening 20, as indicated in the drawing, enables the liquid inlet port 16 to admit liquid only while the vapor finds a low impedance path through the opening 20 in conduit 24 to escape from the pump 10. By virtue of the inclusion of the vapor venting conduit 24 time is saved thereby reducing the period of the operating cycle.

The vapor push pump will operate even if a gas is dissolved in the liquid and later on escapes.

chamber and said outlet opening of said second conduit being located above the liquid level of said external body of liquid, said second conduit passing in sealed relationship through said housing; heating means within said housing but energizable from without said housing for vaporizing at least part of the liquid in said chamber to enable the vapor pressure produced therein to push the liquid in said chamber into the inlet opening of said second conduit and through said second conduit so that the liquid is dischargeable at said outlet opening of said second conduit; a mass of thermal insulation material in said chamber, said mass including a first bore closed at an upper end thereof, said upper end of said first bore being enlarged to define a vapor accumulation space, said heating means being located in said first bore below said vapor accumulation space; a vapor outlet tube passing in sealed relationship through said closed upper end, said tube conducting vapor from said vapor accumulation space to said chamber above the level of liquid in said chamber, said mass of thermal insulation material including a well formed therein for receiving the portion of said second conduit which includes said inlet opening, said mass including a second bore for communicating the liquid in said chamber with said first bore, said well having a liquid exposing surface area just a little larger than the area of the inlet Although one more or less specific embodiment of the invention has been described and illustrated in the accompanying drawing it is to be understood that this has been done for purposes of providing a working example of the invention and that many changes, not departing from the inventive principle involved, will occur to those skilled in the art. The scope of the invention is, however, to be determined from the claims hereinafter set forth. What is claimed is:

l. A vapor push pump comprising: a housing adapted for at least partial submersion below a liquid level of an external body of liquid to be pumped, said housing including a chamber thereof and a port therethrough through which liquid from said external body of liquid may enter the housing and at least partly fill said chamber therein; a first conduit connected to said housing and having inlet and outlet openings, said inlet opening of said first conduit defining a communicating path between said chamber and said first conduit for venting vapor from said chamber through said first conduit, said outlet opening of said first conduit being located above said liquid level of said external body of liquid; a second conduit having inlet and outlet openings at opposite ends thereof, said inlet opening of said second conduit being normally submerged in liquid in said opening of said second conduit; and, a buoyant valve body within said chamber, movable in response to the difference between the force exerted by the liquid level of said external body of liquid through said port on said valve body and the algebraic sum of the forces represented by the weight of the valve body, the buoyant force exerted by the liquid in the chamber on the valve body and the force on the valve body due to the vapor pressure of the vapor in said chamber and surface tension, for closing said port and inlet opening of said first conduit.

2. The vapor push pump according to claim 1 wherein said heating means is an electrical heating element.

3. The vapor push pump according to claim 1 wherein said valve body includes a flexible diaphragm which effects sealed closure of said port and said inlet opening of said first conduit.

4. The vapor push pump according to claim 1 wherein said port and said inlet opening of said first conduit are below the liquid level of the external body of liquid but above the inlet opening of said second conduit.

5. The vapor push pump according to claim 4 wherein said port and said inlet opening of said first conduit are at substantially the same level.

6. The vapor push pump according to claim 5 wherein said valve body includes a flexible diaphragm which effects sealed closure of said port and said inlet opening of said first conduit nearly simultaneously. 

1. A vapor push pump comprising: a housing adapted for at least partial submersion below a liquid level of an external body of liquid to be pumped, said housing including a chamber thereof and a port therethrough through which liquid from said external body of liquid may enter the housing and at least partly fill said chamber therein; a first conduit connected to said housing and having inlet and outlet openings, said inlet opening of said first conduit defining a communicating path between said chamber and said first conduit for venting vapor from said chamber through said first conduit, said outlet opening of said first conduit being located above said liquid level of said external body of liquid; a second conduit having inlet and outlet openings at opposite ends thereof, said inlet opening of said second conduit being normally submerged in liquid in said chamber and said outlet opening of said second conduit being located above the liquid level of said external body of liquid, said second conduit passing in sealed relationship through said housing; heating means within said housing but energizable from without said housing for vaporizing at least part of the liquid in said chamber to enable the vapor pressure produced therein to push the liquid in said chamber into the inlet opening of said second conduit and through said second conduit so that the liquid is dischargeable at said outlet opening of said second conduit; a mass of thermal insulation material in said chamber, said mass including a first bore closed at an upper end thereof, said upper end of said first bore being enlarged to define a vapor accumulation space, said heating means being located in said first bore below said vapor accumulation space; a vapor outlet tube passing in sealed relationship through said closed upper end, said tube conducting vapor from said vapor accumulation space to said chamber above the level of liquid in said chamber, said mass of thermal insulation material including a well formed therein for receiving the portion of said second conduit which includes said inlet opening, said mass including a second bore for communicating the liquid in said chamber with said first bore, said well having a liquid exposing surface area just a little larger than the area of the inlet opening of said second conduit; and, a buoyant valve body within said chamber, movable in response to the difference between the force exerted by the liquid level of said external body of liquid through said port on said valve body and the algebraic sum of the forces represented by the weight of the valve body, the buoyant force exerted by the liquid in the chamber on the valve body and the force on the valve body due to the vapor pressure of the vapor in said chamber and surface tension, for closing said port and inlet opening of said first conduit.
 2. The vapor push pump according to claim 1 wherein said heating means is an electrical heating element.
 3. The vapor push pump according to claim 1 wherein said valve body includes a flexible diaphragm which effects sealed closure of said port and said inlet opening of said first conduit.
 4. The vapor push pump according to claim 1 wherein said port and said inlet opening of said first conduit are below the liquid level of the external body of liquid but above the inlet opening of said second conduit.
 5. The vapor push pump according to claim 4 wHerein said port and said inlet opening of said first conduit are at substantially the same level.
 6. The vapor push pump according to claim 5 wherein said valve body includes a flexible diaphragm which effects sealed closure of said port and said inlet opening of said first conduit nearly simultaneously. 